Individuals incurring arm injuries, or who undergo arm surgery, tend to have limited range of motion in that arm. Even those who have full range of motion, experience difficulty and pain when attempting to articulate their arm in supine or pronate orientations. This inability to articulate the arm compounds problems associated with supine and pronate surgical procedures. It is not only important to remain still during surgery, but it is just as important to position a member of the body in a certain orientation in order to perform the surgery well. Additionally, physical therapy and occupational therapy require proper posture and form when performing range of motion exercises in order to prevent further injury. Accordingly, there exists a need for a means by which an articulating armrest can be utilized during surgery or therapy to support the arm in a salutary posture while still being able to motion the arm in a desired position. The development of the present invention fulfills this need.